title: Error vector magnitude based parameter estimation for digital filter back-propagation mitigating SOA distortions in 16-QAM.
abstract: We investigate the performance of digital filter back-propagation (DFBP) using coarse parameter estimation for mitigating SOA nonlinearity in coherent communication systems. We introduce a simple, low overhead method for parameter estimation for DFBP based on error vector magnitude (EVM) as a figure of merit. The bit error rate (BER) penalty achieved with this method has negligible penalty as compared to DFBP with fine parameter estimation. We examine different bias currents for two commercial SOAs used as booster amplifiers in our experiments to find optimum operating points and experimentally validate our method. The coarse parameter DFBP efficiently compensates SOA-induced nonlinearity for both SOA types in 80 km propagation of 16-QAM signal at 22 Gbaud.
authors.forename: Siamak
authors.initials: S
authors.lastname: Amiralizadeh
authors.forename: An T
authors.initials: AT
authors.lastname: Nguyen
authors.forename: Leslie A
authors.initials: LA
authors.lastname: Rusch